Progressive distributors are conventionally known. A progressive distributor consists of several distributor segments, each having a piston provided with annular grooves that is alternately pressed in two directions by a lubricant, generally lubricating grease or lubricating oil. With the aid of their annular grooves, the pistons are controlled in a defined sequence such that the next piston can be displaced only when the piston motion of the preceding piston is nearly finished. All piston bores are directly connected to the outlet. The progressive distributors can be stopped and restarted in any desired position.
For such progressive distributors of the type used, for example, in central lubrication systems, there is the need for a lasting, reliable and precise metering of the lubricant amount.